I wonder the same thing about myself! At some point I think we get it in our heads that we don't have time for the handwork, we must focus on the things we can finish expediently. I'm so enjoying switching my focus a bit this year and pulling some hand stitching to top priority.

So - have you really tried to figure it out or are you just still wondering? I suppose you know the saying "if it weren't for the last minute a lot of things in the world would never get done"... I find that working at a steady pace without deadlines is very interesting, too, but deadlinnes just speed up the creative process. It must be some juices in the brain - hey, you have the biology background, don't you?